JP2001082590A - Oil temperature adjusting device for hydraulic actuation type gearbox - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accelerate the temperature rising of working oil when it is cold, in order to enhance fuel consumption performance, by providing a heat exchanger to exchange heat between the working oil and the cooling water of an engine, in an oil temperature adjusting device to adjust the oil temperature of the working oil of a hydraulic actuation type gearbox linked to the engine. SOLUTION: A hydraulic circuit 9 in a hydraulic actuation type gearbox structured by providing a sub-gearbox on the output side of a fluid torque converter linked to an engine has a hydraulic pump 10 to suck up working oil in a gearbox case, and supplies the working oil adjusted to a line pressure by a regulator 11 to a speed-changing control part 12. It also supplies the working oil leaked from the regulator 11 to the control part 13 for a lockup clutch(LC) 3a. A drain oil path 14 to return the working oil drained from the fluid torque converter 3 to the gearbox case is connected to the LC control part 13, and the temperature of the working oil can be raised by cooling water for the engine 2 in a heat exchanger 15 interposed in the drain oil path 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil temperature adjusting device mainly applied to a hydraulically operated transmission for a vehicle.

[0002]

2. Description of the Related Art A hydraulically operated transmission for a vehicle includes a fluid torque converter connected to an engine, and an auxiliary transmission having a transmission hydraulic clutch provided on the output side of the fluid torque converter. The fluid torque converter is provided with a lock-up clutch that is pushed to the engagement side by the oil pressure of the internal gap and is pushed to the release side by the oil pressure of the back pressure chamber in the fluid torque converter. By controlling the pressure difference from the hydraulic pressure of the pressure chamber, the lock-up clutch is engaged in a directly connected state or engaged in a sliding state.

Here, when the lock-up clutch is engaged in a sliding state, the oil temperature of the hydraulic oil rises due to frictional heat. Therefore, conventionally, the drain oil from the fluid torque converter is returned to the inside of the transmission case via a radiator pipe arranged on the rear portion of the radiator to prevent the oil temperature of the hydraulic oil of the transmission from rising. I have.

[0004]

When the oil temperature of the hydraulic oil of the transmission decreases, the friction loss of the transmission increases due to the increase in the viscosity of the hydraulic oil, and the fuel efficiency of the engine deteriorates. However, conventionally, only attention has been paid to preventing the temperature of the hydraulic oil from rising, and when the outside air temperature is lowered, the rise in the operating temperature is delayed, and the fuel efficiency is adversely affected.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide an oil temperature adjusting device for a hydraulically operated transmission which can improve the fuel efficiency by promoting the temperature rise of hydraulic oil in cold weather. And

[0006]

Means for Solving the Problems In order to solve the above problems,
The present invention provides a device for adjusting the oil temperature of hydraulic oil of a hydraulically operated transmission connected to an engine, wherein a heat exchanger for exchanging heat between the hydraulic oil and cooling water of the engine is provided.

[0007] The temperature of the engine cooling water rises early after the engine is started, and heat exchange with the cooling water promotes the temperature rise of the working oil. Thus, even in cold weather, the temperature of the hydraulic oil is quickly raised, the friction loss of the transmission is reduced, and the fuel efficiency is improved.

Further, when the oil temperature of the hydraulic oil becomes equal to or higher than a predetermined temperature, the engine cooling water functions as a refrigerant to cool the hydraulic oil and prevent overheating of the hydraulic oil.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numeral 1 denotes a hydraulically operated transmission for a vehicle. The transmission 1 includes a fluid torque converter 3 connected to an engine 2, and an output of the fluid torque converter 3. And the auxiliary transmission 4 provided on the side.

The auxiliary transmission 4 includes a first input shaft 4a connected to the fluid torque converter 3, a second input shaft 4b that rotates synchronously with the first input shaft 4a, and a differential gear 6 for driving wheels 5 of the vehicle.
And an output shaft 4c connected through the second input shaft 4
b and the output shaft 4c, the first and second forward speeds G1 and G2 are juxtaposed, and the third to fifth speeds for forward movement are provided between the first input shaft 4a and the output shaft 4c. Speed stages G3, G
4, G5 and the reverse gear GR are arranged side by side, and each of these forward gears is provided with hydraulic clutches C1, C2, C3, C4, C5 of the first to fifth gears as hydraulic connecting elements. The forward gears are selectively established by coupling the hydraulic clutches. The reverse gear GR shares the fifth gear G5 and the fifth hydraulic clutch C5, and the fifth gear G5 and the reverse gear are used. GR is selectively established by a switching operation between a leftward forward side and a rightward reverse side in the drawing of the selector gear 7 on the output shaft 4c. The second input shaft 4b is connected to the output shaft 4
The third speed G on the input side of the third speed hydraulic clutch C3 provided on
3 for the first input shaft 4
Rotate synchronously with a.

The first speed G1 has a one-way clutch 8 interposed between the first speed hydraulic clutch C1 and a gear train for the first speed G1 on the output side to allow overspeed on the output side.
The first-speed hydraulic clutch C1 further incorporates a first-speed hold hydraulic clutch CH in which the output side is directly connected to the gear train for the first-speed stage G1 in the first-speed hydraulic clutch C1, and the output-side over-rotation is performed by engagement of the hydraulic clutch CH. Is not allowed, that is, the first gear G1 can be established in a state where the engine brake can be applied.

The fluid torque converter 3 has a built-in lock-up clutch 3a which engages with the end wall of the converter case and connects the input side and the output side of the fluid torque converter 3 to each other. The lock-up clutch 3a is pushed to the engagement side by the oil pressure of the internal gap 3b of the fluid torque converter 3, and is pushed to the release side by the oil pressure of the back pressure chamber 3c between the end wall of the converter case and the lock-up clutch 3b. It is supposed to be.

The hydraulically operated transmission 1 has a hydraulic circuit 9.
Is incorporated. As shown in FIG. 2, the hydraulic circuit 9 includes a hydraulic pump 10 for sucking hydraulic oil in the transmission case.
A regulator 11 for adjusting the discharge pressure of the hydraulic pump 10 to a predetermined line pressure, a shift control unit 12 for supplying hydraulic oil adjusted to the line pressure, and a lock for supplying hydraulic oil leaked from the regulator 11 And a control unit (hereinafter, referred to as an LC control unit) 13 for the up clutch 3a. The shift control unit 12 is configured to control the supply and discharge of oil to and from each of the hydraulic clutches CH, C1, C2, C3, C4, and C5 of the sub-transmission 4 to shift the speed of the sub-transmission 4. In addition, the LC control unit 13 controls the fluid torque converter 3
Control of oil supply / discharge to the internal space 3b and the back pressure chamber 3c of
The lock-up clutch 3a is engaged or disengaged, and further, the differential pressure between the oil pressure in the internal gap 3b and the oil pressure in the back pressure chamber 3c is controlled so that the lock-up clutch 3a is engaged in a directly connected state or in a slip state. It is configured to be engaged.
The shift control unit 12 and the LC control unit 13 are conventionally known, and a detailed description thereof will be omitted.

A drain oil passage 14 for returning the hydraulic oil drained from the fluid torque converter 3 to the inside of the transmission case is connected to the LC control unit 13, and a heat exchanger 15 is provided in the drain oil passage 14. In addition, heat is exchanged between the hydraulic oil and the engine cooling water.

Hereinafter, the heat exchanger 15 will be described including the cooling water circuit of the engine 2. The cooling water circuit is configured to forcibly circulate the cooling water between the engine 2 and the radiator 16 by the water pump 17 and to circulate the cooling water by bypassing the radiator 16 by the thermostat 18 at a low water temperature. Also, a circuit for the air conditioning heater 19 is provided, and when the heater valve 20 interposed in the circuit is opened, a part of the cooling water flowing out of the engine 1 is returned to the water pump 17 via the air conditioning heater 19. ing. Further, a circuit for the heat exchanger 15 is provided in parallel with a circuit for the air conditioning heater 19, and the engine 1
A part of the cooling water flowing out of the pump is returned to the water pump 17 via the heat exchanger 15.

The heat exchanger 15 has the same structure as an oil cooler used for cooling engine oil, and is mounted on a transmission case 1a as shown in FIG. In the figure, 15a and 15b are an inlet hose and an outlet hose of the cooling water.

FIG. 4 shows a change in the coolant temperature and a change in the hydraulic oil temperature of the transmission 1 when the vehicle is run in a running mode called the Los Angeles 4 mode when the outside air temperature is -6.7 ° C. 5 shows a change in vehicle speed. Here, traveling in a phase called CT (Cold Transient) for 500 seconds after the engine is started, and CS (Co
ld Stability), and then one
The vehicle travels in a phase called HT (Hot Transient) for 500 seconds after being left for 0 minutes. As is clear from FIG. 4, when the heat exchanger 15 is provided as in the present embodiment, the working oil is heated by heat exchange with the cooling water that quickly rises in temperature after the engine is started, and the heat exchanger 15 is not provided. The temperature rise of the hydraulic oil is promoted as compared with the case. When the lock-up clutch 3a is engaged in a sliding state, the hydraulic oil may be heated to approximately 170 ° C. due to frictional heat. However, since the cooling water is maintained at approximately 90 ° C. or less, the heated oil is heated. The oil is cooled in the heat exchanger 15, and the oil temperature does not rise abnormally.

FIG. 5 shows the fuel efficiency (mileage per gallon) in each of the above phases. When the heat exchanger 15 is provided in black, the heat exchanger 15 is provided in white. If not. When the heat exchanger 15 is provided, the fuel efficiency becomes C
0.75% in T phase, 1.0 in CS phase
%, 0.98% improvement in the HT phase,
M (Weight Mass)), it was found that fuel efficiency was improved by 0.99%.

In the above embodiment, the heat exchanger 15 is provided in the drain passage 14 from the LC control unit 13. However, the heat exchanger 15 may be provided in another part of the hydraulic circuit 9.

[0020]

As is apparent from the above description, according to the present invention, it is possible to promote the temperature rise of the hydraulic oil at the time of cold, reduce the friction loss of the transmission, and improve the fuel efficiency.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram of an example of a hydraulically operated transmission to which the present invention is applied.

FIG. 2 is a diagram showing a cooling water circuit of an engine and a hydraulic circuit of a transmission.

FIG. 3 is a perspective view in which a part of a heat exchanger is cut away.

FIG. 4 is a graph showing a change in cooling water temperature and a change in hydraulic oil temperature.

FIG. 5 is a graph showing fuel efficiency.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulically operated transmission 2 Engine 9 Hydraulic circuit 15 Heat exchanger

Continued on the front page (72) Inventor Masayuki Tsumaga 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3J063 AA01 AC03 BA15 BA17 CA01 XH02 XH03 XH12 XH25 XH42 XH43

Claims (1)

[Claims] 1. An apparatus for adjusting the oil temperature of hydraulic oil of a hydraulically operated transmission connected to an engine, wherein a heat exchanger for exchanging heat between the hydraulic oil and cooling water of the engine is provided. An oil temperature adjusting device for a hydraulically operated transmission.